diff --git a/library/alloc/src/collections/binary_heap.rs b/library/alloc/src/collections/binary_heap.rs
index e6c3d38dab3a2..37fb901b46323 100644
--- a/library/alloc/src/collections/binary_heap.rs
+++ b/library/alloc/src/collections/binary_heap.rs
@@ -155,6 +155,9 @@ use crate::vec::{self, AsIntoIter, Vec};
 
 use super::SpecExtend;
 
+#[cfg(test)]
+mod tests;
+
 /// A priority queue implemented with a binary heap.
 ///
 /// This will be a max-heap.
diff --git a/library/alloc/tests/binary_heap.rs b/library/alloc/src/collections/binary_heap/tests.rs
similarity index 99%
rename from library/alloc/tests/binary_heap.rs
rename to library/alloc/src/collections/binary_heap/tests.rs
index f32118bb5637e..7c758dbb3ab8a 100644
--- a/library/alloc/tests/binary_heap.rs
+++ b/library/alloc/src/collections/binary_heap/tests.rs
@@ -1,5 +1,5 @@
-use std::collections::binary_heap::{Drain, PeekMut};
-use std::collections::BinaryHeap;
+use super::*;
+use crate::boxed::Box;
 use std::iter::TrustedLen;
 use std::panic::{catch_unwind, AssertUnwindSafe};
 use std::sync::atomic::{AtomicU32, Ordering};
diff --git a/library/alloc/src/collections/linked_list/tests.rs b/library/alloc/src/collections/linked_list/tests.rs
index 5a65ed7a962e9..38c702aa387bd 100644
--- a/library/alloc/src/collections/linked_list/tests.rs
+++ b/library/alloc/src/collections/linked_list/tests.rs
@@ -1,10 +1,55 @@
 use super::*;
+use crate::vec::Vec;
 
+use std::panic::{catch_unwind, AssertUnwindSafe};
 use std::thread;
-use std::vec::Vec;
 
 use rand::{thread_rng, RngCore};
 
+#[test]
+fn test_basic() {
+    let mut m = LinkedList::<Box<_>>::new();
+    assert_eq!(m.pop_front(), None);
+    assert_eq!(m.pop_back(), None);
+    assert_eq!(m.pop_front(), None);
+    m.push_front(box 1);
+    assert_eq!(m.pop_front(), Some(box 1));
+    m.push_back(box 2);
+    m.push_back(box 3);
+    assert_eq!(m.len(), 2);
+    assert_eq!(m.pop_front(), Some(box 2));
+    assert_eq!(m.pop_front(), Some(box 3));
+    assert_eq!(m.len(), 0);
+    assert_eq!(m.pop_front(), None);
+    m.push_back(box 1);
+    m.push_back(box 3);
+    m.push_back(box 5);
+    m.push_back(box 7);
+    assert_eq!(m.pop_front(), Some(box 1));
+
+    let mut n = LinkedList::new();
+    n.push_front(2);
+    n.push_front(3);
+    {
+        assert_eq!(n.front().unwrap(), &3);
+        let x = n.front_mut().unwrap();
+        assert_eq!(*x, 3);
+        *x = 0;
+    }
+    {
+        assert_eq!(n.back().unwrap(), &2);
+        let y = n.back_mut().unwrap();
+        assert_eq!(*y, 2);
+        *y = 1;
+    }
+    assert_eq!(n.pop_front(), Some(0));
+    assert_eq!(n.pop_front(), Some(1));
+}
+
+fn generate_test() -> LinkedList<i32> {
+    list_from(&[0, 1, 2, 3, 4, 5, 6])
+}
+
 fn list_from<T: Clone>(v: &[T]) -> LinkedList<T> {
     v.iter().cloned().collect()
 }
@@ -110,6 +155,123 @@ fn test_append() {
     check_links(&n);
 }
 
+#[test]
+fn test_iterator() {
+    let m = generate_test();
+    for (i, elt) in m.iter().enumerate() {
+        assert_eq!(i as i32, *elt);
+    }
+    let mut n = LinkedList::new();
+    assert_eq!(n.iter().next(), None);
+    n.push_front(4);
+    let mut it = n.iter();
+    assert_eq!(it.size_hint(), (1, Some(1)));
+    assert_eq!(it.next().unwrap(), &4);
+    assert_eq!(it.size_hint(), (0, Some(0)));
+    assert_eq!(it.next(), None);
+}
+
+#[test]
+fn test_iterator_clone() {
+    let mut n = LinkedList::new();
+    n.push_back(2);
+    n.push_back(3);
+    n.push_back(4);
+    let mut it = n.iter();
+    it.next();
+    let mut jt = it.clone();
+    assert_eq!(it.next(), jt.next());
+    assert_eq!(it.next_back(), jt.next_back());
+    assert_eq!(it.next(), jt.next());
+}
+
+#[test]
+fn test_iterator_double_end() {
+    let mut n = LinkedList::new();
+    assert_eq!(n.iter().next(), None);
+    n.push_front(4);
+    n.push_front(5);
+    n.push_front(6);
+    let mut it = n.iter();
+    assert_eq!(it.size_hint(), (3, Some(3)));
+    assert_eq!(it.next().unwrap(), &6);
+    assert_eq!(it.size_hint(), (2, Some(2)));
+    assert_eq!(it.next_back().unwrap(), &4);
+    assert_eq!(it.size_hint(), (1, Some(1)));
+    assert_eq!(it.next_back().unwrap(), &5);
+    assert_eq!(it.next_back(), None);
+    assert_eq!(it.next(), None);
+}
+
+#[test]
+fn test_rev_iter() {
+    let m = generate_test();
+    for (i, elt) in m.iter().rev().enumerate() {
+        assert_eq!((6 - i) as i32, *elt);
+    }
+    let mut n = LinkedList::new();
+    assert_eq!(n.iter().rev().next(), None);
+    n.push_front(4);
+    let mut it = n.iter().rev();
+    assert_eq!(it.size_hint(), (1, Some(1)));
+    assert_eq!(it.next().unwrap(), &4);
+    assert_eq!(it.size_hint(), (0, Some(0)));
+    assert_eq!(it.next(), None);
+}
+
+#[test]
+fn test_mut_iter() {
+    let mut m = generate_test();
+    let mut len = m.len();
+    for (i, elt) in m.iter_mut().enumerate() {
+        assert_eq!(i as i32, *elt);
+        len -= 1;
+    }
+    assert_eq!(len, 0);
+    let mut n = LinkedList::new();
+    assert!(n.iter_mut().next().is_none());
+    n.push_front(4);
+    n.push_back(5);
+    let mut it = n.iter_mut();
+    assert_eq!(it.size_hint(), (2, Some(2)));
+    assert!(it.next().is_some());
+    assert!(it.next().is_some());
+    assert_eq!(it.size_hint(), (0, Some(0)));
+    assert!(it.next().is_none());
+}
+
+#[test]
+fn test_iterator_mut_double_end() {
+    let mut n = LinkedList::new();
+    assert!(n.iter_mut().next_back().is_none());
+    n.push_front(4);
+    n.push_front(5);
+    n.push_front(6);
+    let mut it = n.iter_mut();
+    assert_eq!(it.size_hint(), (3, Some(3)));
+    assert_eq!(*it.next().unwrap(), 6);
+    assert_eq!(it.size_hint(), (2, Some(2)));
+    assert_eq!(*it.next_back().unwrap(), 4);
+    assert_eq!(it.size_hint(), (1, Some(1)));
+    assert_eq!(*it.next_back().unwrap(), 5);
+    assert!(it.next_back().is_none());
+    assert!(it.next().is_none());
+}
+
+#[test]
+fn test_mut_rev_iter() {
+    let mut m = generate_test();
+    for (i, elt) in m.iter_mut().rev().enumerate() {
+        assert_eq!((6 - i) as i32, *elt);
+    }
+    let mut n = LinkedList::new();
+    assert!(n.iter_mut().rev().next().is_none());
+    n.push_front(4);
+    let mut it = n.iter_mut().rev();
+    assert!(it.next().is_some());
+    assert!(it.next().is_none());
+}
+
 #[test]
 fn test_clone_from() {
     // Short cloned from long
@@ -168,13 +330,60 @@ fn test_send() {
 }
 
 #[test]
-fn test_fuzz() {
-    for _ in 0..25 {
-        fuzz_test(3);
-        fuzz_test(16);
-        #[cfg(not(miri))] // Miri is too slow
-        fuzz_test(189);
-    }
+fn test_eq() {
+    let mut n = list_from(&[]);
+    let mut m = list_from(&[]);
+    assert!(n == m);
+    n.push_front(1);
+    assert!(n != m);
+    m.push_back(1);
+    assert!(n == m);
+
+    let n = list_from(&[2, 3, 4]);
+    let m = list_from(&[1, 2, 3]);
+    assert!(n != m);
+}
+
+#[test]
+fn test_ord() {
+    let n = list_from(&[]);
+    let m = list_from(&[1, 2, 3]);
+    assert!(n < m);
+    assert!(m > n);
+    assert!(n <= n);
+    assert!(n >= n);
+}
+
+#[test]
+fn test_ord_nan() {
+    let nan = 0.0f64 / 0.0;
+    let n = list_from(&[nan]);
+    let m = list_from(&[nan]);
+    assert!(!(n < m));
+    assert!(!(n > m));
+    assert!(!(n <= m));
+    assert!(!(n >= m));
+
+    let n = list_from(&[nan]);
+    let one = list_from(&[1.0f64]);
+    assert!(!(n < one));
+    assert!(!(n > one));
+    assert!(!(n <= one));
+    assert!(!(n >= one));
+
+    let u = list_from(&[1.0f64, 2.0, nan]);
+    let v = list_from(&[1.0f64, 2.0, 3.0]);
+    assert!(!(u < v));
+    assert!(!(u > v));
+    assert!(!(u <= v));
+    assert!(!(u >= v));
+
+    let s = list_from(&[1.0f64, 2.0, 4.0, 2.0]);
+    let t = list_from(&[1.0f64, 2.0, 3.0, 2.0]);
+    assert!(!(s < t));
+    assert!(s > one);
+    assert!(!(s <= one));
+    assert!(s >= one);
 }
 
 #[test]
@@ -215,6 +424,62 @@ fn test_split_off() {
     }
 }
 
+#[test]
+fn test_split_off_2() {
+    // singleton
+    {
+        let mut m = LinkedList::new();
+        m.push_back(1);
+
+        let p = m.split_off(0);
+        assert_eq!(m.len(), 0);
+        assert_eq!(p.len(), 1);
+        assert_eq!(p.back(), Some(&1));
+        assert_eq!(p.front(), Some(&1));
+    }
+
+    // not singleton, forwards
+    {
+        let u = vec![1, 2, 3, 4, 5];
+        let mut m = list_from(&u);
+        let mut n = m.split_off(2);
+        assert_eq!(m.len(), 2);
+        assert_eq!(n.len(), 3);
+        for elt in 1..3 {
+            assert_eq!(m.pop_front(), Some(elt));
+        }
+        for elt in 3..6 {
+            assert_eq!(n.pop_front(), Some(elt));
+        }
+    }
+    // not singleton, backwards
+    {
+        let u = vec![1, 2, 3, 4, 5];
+        let mut m = list_from(&u);
+        let mut n = m.split_off(4);
+        assert_eq!(m.len(), 4);
+        assert_eq!(n.len(), 1);
+        for elt in 1..5 {
+            assert_eq!(m.pop_front(), Some(elt));
+        }
+        for elt in 5..6 {
+            assert_eq!(n.pop_front(), Some(elt));
+        }
+    }
+
+    // no-op on the last index
+    {
+        let mut m = LinkedList::new();
+        m.push_back(1);
+
+        let p = m.split_off(1);
+        assert_eq!(m.len(), 1);
+        assert_eq!(p.len(), 0);
+        assert_eq!(m.back(), Some(&1));
+        assert_eq!(m.front(), Some(&1));
+    }
+}
+
 fn fuzz_test(sz: i32) {
     let mut m: LinkedList<_> = LinkedList::new();
     let mut v = vec![];
@@ -253,6 +518,25 @@ fn fuzz_test(sz: i32) {
     assert_eq!(i, v.len());
 }
 
+#[test]
+fn test_fuzz() {
+    for _ in 0..25 {
+        fuzz_test(3);
+        fuzz_test(16);
+        #[cfg(not(miri))] // Miri is too slow
+        fuzz_test(189);
+    }
+}
+
+#[test]
+fn test_show() {
+    let list: LinkedList<_> = (0..10).collect();
+    assert_eq!(format!("{list:?}"), "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]");
+
+    let list: LinkedList<_> = ["just", "one", "test", "more"].into_iter().collect();
+    assert_eq!(format!("{list:?}"), "[\"just\", \"one\", \"test\", \"more\"]");
+}
+
 #[test]
 fn drain_filter_test() {
     let mut m: LinkedList<u32> = LinkedList::new();
@@ -475,3 +759,398 @@ fn test_cursor_pop_front_back() {
     assert_eq!(c.current(), None);
     assert_eq!(c.index, 2);
 }
+
+#[test]
+fn test_extend_ref() {
+    let mut a = LinkedList::new();
+    a.push_back(1);
+
+    a.extend(&[2, 3, 4]);
+
+    assert_eq!(a.len(), 4);
+    assert_eq!(a, list_from(&[1, 2, 3, 4]));
+
+    let mut b = LinkedList::new();
+    b.push_back(5);
+    b.push_back(6);
+    a.extend(&b);
+
+    assert_eq!(a.len(), 6);
+    assert_eq!(a, list_from(&[1, 2, 3, 4, 5, 6]));
+}
+
+#[test]
+fn test_extend() {
+    let mut a = LinkedList::new();
+    a.push_back(1);
+    a.extend(vec![2, 3, 4]); // uses iterator
+
+    assert_eq!(a.len(), 4);
+    assert!(a.iter().eq(&[1, 2, 3, 4]));
+
+    let b: LinkedList<_> = [5, 6, 7].into_iter().collect();
+    a.extend(b); // specializes to `append`
+
+    assert_eq!(a.len(), 7);
+    assert!(a.iter().eq(&[1, 2, 3, 4, 5, 6, 7]));
+}
+
+#[test]
+fn test_contains() {
+    let mut l = LinkedList::new();
+    l.extend(&[2, 3, 4]);
+
+    assert!(l.contains(&3));
+    assert!(!l.contains(&1));
+
+    l.clear();
+
+    assert!(!l.contains(&3));
+}
+
+#[test]
+fn drain_filter_empty() {
+    let mut list: LinkedList<i32> = LinkedList::new();
+
+    {
+        let mut iter = list.drain_filter(|_| true);
+        assert_eq!(iter.size_hint(), (0, Some(0)));
+        assert_eq!(iter.next(), None);
+        assert_eq!(iter.size_hint(), (0, Some(0)));
+        assert_eq!(iter.next(), None);
+        assert_eq!(iter.size_hint(), (0, Some(0)));
+    }
+
+    assert_eq!(list.len(), 0);
+    assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![]);
+}
+
+#[test]
+fn drain_filter_zst() {
+    let mut list: LinkedList<_> = [(), (), (), (), ()].into_iter().collect();
+    let initial_len = list.len();
+    let mut count = 0;
+
+    {
+        let mut iter = list.drain_filter(|_| true);
+        assert_eq!(iter.size_hint(), (0, Some(initial_len)));
+        while let Some(_) = iter.next() {
+            count += 1;
+            assert_eq!(iter.size_hint(), (0, Some(initial_len - count)));
+        }
+        assert_eq!(iter.size_hint(), (0, Some(0)));
+        assert_eq!(iter.next(), None);
+        assert_eq!(iter.size_hint(), (0, Some(0)));
+    }
+
+    assert_eq!(count, initial_len);
+    assert_eq!(list.len(), 0);
+    assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![]);
+}
+
+#[test]
+fn drain_filter_false() {
+    let mut list: LinkedList<_> = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].into_iter().collect();
+
+    let initial_len = list.len();
+    let mut count = 0;
+
+    {
+        let mut iter = list.drain_filter(|_| false);
+        assert_eq!(iter.size_hint(), (0, Some(initial_len)));
+        for _ in iter.by_ref() {
+            count += 1;
+        }
+        assert_eq!(iter.size_hint(), (0, Some(0)));
+        assert_eq!(iter.next(), None);
+        assert_eq!(iter.size_hint(), (0, Some(0)));
+    }
+
+    assert_eq!(count, 0);
+    assert_eq!(list.len(), initial_len);
+    assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
+}
+
+#[test]
+fn drain_filter_true() {
+    let mut list: LinkedList<_> = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].into_iter().collect();
+
+    let initial_len = list.len();
+    let mut count = 0;
+
+    {
+        let mut iter = list.drain_filter(|_| true);
+        assert_eq!(iter.size_hint(), (0, Some(initial_len)));
+        while let Some(_) = iter.next() {
+            count += 1;
+            assert_eq!(iter.size_hint(), (0, Some(initial_len - count)));
+        }
+        assert_eq!(iter.size_hint(), (0, Some(0)));
+        assert_eq!(iter.next(), None);
+        assert_eq!(iter.size_hint(), (0, Some(0)));
+    }
+
+    assert_eq!(count, initial_len);
+    assert_eq!(list.len(), 0);
+    assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![]);
+}
+
+#[test]
+fn drain_filter_complex() {
+    {
+        //                [+xxx++++++xxxxx++++x+x++]
+        let mut list = [
+            1, 2, 4, 6, 7, 9, 11, 13, 15, 17, 18, 20, 22, 24, 26, 27, 29, 31, 33, 34, 35, 36, 37,
+            39,
+        ]
+        .into_iter()
+        .collect::<LinkedList<_>>();
+
+        let removed = list.drain_filter(|x| *x % 2 == 0).collect::<Vec<_>>();
+        assert_eq!(removed.len(), 10);
+        assert_eq!(removed, vec![2, 4, 6, 18, 20, 22, 24, 26, 34, 36]);
+
+        assert_eq!(list.len(), 14);
+        assert_eq!(
+            list.into_iter().collect::<Vec<_>>(),
+            vec![1, 7, 9, 11, 13, 15, 17, 27, 29, 31, 33, 35, 37, 39]
+        );
+    }
+
+    {
+        // [xxx++++++xxxxx++++x+x++]
+        let mut list =
+            [2, 4, 6, 7, 9, 11, 13, 15, 17, 18, 20, 22, 24, 26, 27, 29, 31, 33, 34, 35, 36, 37, 39]
+                .into_iter()
+                .collect::<LinkedList<_>>();
+
+        let removed = list.drain_filter(|x| *x % 2 == 0).collect::<Vec<_>>();
+        assert_eq!(removed.len(), 10);
+        assert_eq!(removed, vec![2, 4, 6, 18, 20, 22, 24, 26, 34, 36]);
+
+        assert_eq!(list.len(), 13);
+        assert_eq!(
+            list.into_iter().collect::<Vec<_>>(),
+            vec![7, 9, 11, 13, 15, 17, 27, 29, 31, 33, 35, 37, 39]
+        );
+    }
+
+    {
+        // [xxx++++++xxxxx++++x+x]
+        let mut list =
+            [2, 4, 6, 7, 9, 11, 13, 15, 17, 18, 20, 22, 24, 26, 27, 29, 31, 33, 34, 35, 36]
+                .into_iter()
+                .collect::<LinkedList<_>>();
+
+        let removed = list.drain_filter(|x| *x % 2 == 0).collect::<Vec<_>>();
+        assert_eq!(removed.len(), 10);
+        assert_eq!(removed, vec![2, 4, 6, 18, 20, 22, 24, 26, 34, 36]);
+
+        assert_eq!(list.len(), 11);
+        assert_eq!(
+            list.into_iter().collect::<Vec<_>>(),
+            vec![7, 9, 11, 13, 15, 17, 27, 29, 31, 33, 35]
+        );
+    }
+
+    {
+        // [xxxxxxxxxx+++++++++++]
+        let mut list = [2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19]
+            .into_iter()
+            .collect::<LinkedList<_>>();
+
+        let removed = list.drain_filter(|x| *x % 2 == 0).collect::<Vec<_>>();
+        assert_eq!(removed.len(), 10);
+        assert_eq!(removed, vec![2, 4, 6, 8, 10, 12, 14, 16, 18, 20]);
+
+        assert_eq!(list.len(), 10);
+        assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![1, 3, 5, 7, 9, 11, 13, 15, 17, 19]);
+    }
+
+    {
+        // [+++++++++++xxxxxxxxxx]
+        let mut list = [1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20]
+            .into_iter()
+            .collect::<LinkedList<_>>();
+
+        let removed = list.drain_filter(|x| *x % 2 == 0).collect::<Vec<_>>();
+        assert_eq!(removed.len(), 10);
+        assert_eq!(removed, vec![2, 4, 6, 8, 10, 12, 14, 16, 18, 20]);
+
+        assert_eq!(list.len(), 10);
+        assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![1, 3, 5, 7, 9, 11, 13, 15, 17, 19]);
+    }
+}
+
+#[test]
+fn drain_filter_drop_panic_leak() {
+    static mut DROPS: i32 = 0;
+
+    struct D(bool);
+
+    impl Drop for D {
+        fn drop(&mut self) {
+            unsafe {
+                DROPS += 1;
+            }
+
+            if self.0 {
+                panic!("panic in `drop`");
+            }
+        }
+    }
+
+    let mut q = LinkedList::new();
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_front(D(false));
+    q.push_front(D(true));
+    q.push_front(D(false));
+
+    catch_unwind(AssertUnwindSafe(|| drop(q.drain_filter(|_| true)))).ok();
+
+    assert_eq!(unsafe { DROPS }, 8);
+    assert!(q.is_empty());
+}
+
+#[test]
+fn drain_filter_pred_panic_leak() {
+    static mut DROPS: i32 = 0;
+
+    #[derive(Debug)]
+    struct D(u32);
+
+    impl Drop for D {
+        fn drop(&mut self) {
+            unsafe {
+                DROPS += 1;
+            }
+        }
+    }
+
+    let mut q = LinkedList::new();
+    q.push_back(D(3));
+    q.push_back(D(4));
+    q.push_back(D(5));
+    q.push_back(D(6));
+    q.push_back(D(7));
+    q.push_front(D(2));
+    q.push_front(D(1));
+    q.push_front(D(0));
+
+    catch_unwind(AssertUnwindSafe(|| {
+        drop(q.drain_filter(|item| if item.0 >= 2 { panic!() } else { true }))
+    }))
+    .ok();
+
+    assert_eq!(unsafe { DROPS }, 2); // 0 and 1
+    assert_eq!(q.len(), 6);
+}
+
+#[test]
+fn test_drop() {
+    static mut DROPS: i32 = 0;
+    struct Elem;
+    impl Drop for Elem {
+        fn drop(&mut self) {
+            unsafe {
+                DROPS += 1;
+            }
+        }
+    }
+
+    let mut ring = LinkedList::new();
+    ring.push_back(Elem);
+    ring.push_front(Elem);
+    ring.push_back(Elem);
+    ring.push_front(Elem);
+    drop(ring);
+
+    assert_eq!(unsafe { DROPS }, 4);
+}
+
+#[test]
+fn test_drop_with_pop() {
+    static mut DROPS: i32 = 0;
+    struct Elem;
+    impl Drop for Elem {
+        fn drop(&mut self) {
+            unsafe {
+                DROPS += 1;
+            }
+        }
+    }
+
+    let mut ring = LinkedList::new();
+    ring.push_back(Elem);
+    ring.push_front(Elem);
+    ring.push_back(Elem);
+    ring.push_front(Elem);
+
+    drop(ring.pop_back());
+    drop(ring.pop_front());
+    assert_eq!(unsafe { DROPS }, 2);
+
+    drop(ring);
+    assert_eq!(unsafe { DROPS }, 4);
+}
+
+#[test]
+fn test_drop_clear() {
+    static mut DROPS: i32 = 0;
+    struct Elem;
+    impl Drop for Elem {
+        fn drop(&mut self) {
+            unsafe {
+                DROPS += 1;
+            }
+        }
+    }
+
+    let mut ring = LinkedList::new();
+    ring.push_back(Elem);
+    ring.push_front(Elem);
+    ring.push_back(Elem);
+    ring.push_front(Elem);
+    ring.clear();
+    assert_eq!(unsafe { DROPS }, 4);
+
+    drop(ring);
+    assert_eq!(unsafe { DROPS }, 4);
+}
+
+#[test]
+fn test_drop_panic() {
+    static mut DROPS: i32 = 0;
+
+    struct D(bool);
+
+    impl Drop for D {
+        fn drop(&mut self) {
+            unsafe {
+                DROPS += 1;
+            }
+
+            if self.0 {
+                panic!("panic in `drop`");
+            }
+        }
+    }
+
+    let mut q = LinkedList::new();
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_back(D(false));
+    q.push_front(D(false));
+    q.push_front(D(false));
+    q.push_front(D(true));
+
+    catch_unwind(move || drop(q)).ok();
+
+    assert_eq!(unsafe { DROPS }, 8);
+}
diff --git a/library/alloc/tests/lib.rs b/library/alloc/tests/lib.rs
index cbb86265233b0..fb6468ef30f2d 100644
--- a/library/alloc/tests/lib.rs
+++ b/library/alloc/tests/lib.rs
@@ -44,7 +44,6 @@ use std::collections::hash_map::DefaultHasher;
 use std::hash::{Hash, Hasher};
 
 mod arc;
-mod binary_heap;
 mod borrow;
 mod boxed;
 mod btree_set_hash;
diff --git a/library/alloc/tests/linked_list.rs b/library/alloc/tests/linked_list.rs
index 66a9cca6644c4..65b09cb00c45d 100644
--- a/library/alloc/tests/linked_list.rs
+++ b/library/alloc/tests/linked_list.rs
@@ -1,241 +1,4 @@
 use std::collections::LinkedList;
-use std::panic::{catch_unwind, AssertUnwindSafe};
-
-#[test]
-fn test_basic() {
-    let mut m = LinkedList::<Box<_>>::new();
-    assert_eq!(m.pop_front(), None);
-    assert_eq!(m.pop_back(), None);
-    assert_eq!(m.pop_front(), None);
-    m.push_front(box 1);
-    assert_eq!(m.pop_front(), Some(box 1));
-    m.push_back(box 2);
-    m.push_back(box 3);
-    assert_eq!(m.len(), 2);
-    assert_eq!(m.pop_front(), Some(box 2));
-    assert_eq!(m.pop_front(), Some(box 3));
-    assert_eq!(m.len(), 0);
-    assert_eq!(m.pop_front(), None);
-    m.push_back(box 1);
-    m.push_back(box 3);
-    m.push_back(box 5);
-    m.push_back(box 7);
-    assert_eq!(m.pop_front(), Some(box 1));
-
-    let mut n = LinkedList::new();
-    n.push_front(2);
-    n.push_front(3);
-    {
-        assert_eq!(n.front().unwrap(), &3);
-        let x = n.front_mut().unwrap();
-        assert_eq!(*x, 3);
-        *x = 0;
-    }
-    {
-        assert_eq!(n.back().unwrap(), &2);
-        let y = n.back_mut().unwrap();
-        assert_eq!(*y, 2);
-        *y = 1;
-    }
-    assert_eq!(n.pop_front(), Some(0));
-    assert_eq!(n.pop_front(), Some(1));
-}
-
-fn generate_test() -> LinkedList<i32> {
-    list_from(&[0, 1, 2, 3, 4, 5, 6])
-}
-
-fn list_from<T: Clone>(v: &[T]) -> LinkedList<T> {
-    v.iter().cloned().collect()
-}
-
-#[test]
-fn test_split_off() {
-    // singleton
-    {
-        let mut m = LinkedList::new();
-        m.push_back(1);
-
-        let p = m.split_off(0);
-        assert_eq!(m.len(), 0);
-        assert_eq!(p.len(), 1);
-        assert_eq!(p.back(), Some(&1));
-        assert_eq!(p.front(), Some(&1));
-    }
-
-    // not singleton, forwards
-    {
-        let u = vec![1, 2, 3, 4, 5];
-        let mut m = list_from(&u);
-        let mut n = m.split_off(2);
-        assert_eq!(m.len(), 2);
-        assert_eq!(n.len(), 3);
-        for elt in 1..3 {
-            assert_eq!(m.pop_front(), Some(elt));
-        }
-        for elt in 3..6 {
-            assert_eq!(n.pop_front(), Some(elt));
-        }
-    }
-    // not singleton, backwards
-    {
-        let u = vec![1, 2, 3, 4, 5];
-        let mut m = list_from(&u);
-        let mut n = m.split_off(4);
-        assert_eq!(m.len(), 4);
-        assert_eq!(n.len(), 1);
-        for elt in 1..5 {
-            assert_eq!(m.pop_front(), Some(elt));
-        }
-        for elt in 5..6 {
-            assert_eq!(n.pop_front(), Some(elt));
-        }
-    }
-
-    // no-op on the last index
-    {
-        let mut m = LinkedList::new();
-        m.push_back(1);
-
-        let p = m.split_off(1);
-        assert_eq!(m.len(), 1);
-        assert_eq!(p.len(), 0);
-        assert_eq!(m.back(), Some(&1));
-        assert_eq!(m.front(), Some(&1));
-    }
-}
-
-#[test]
-fn test_iterator() {
-    let m = generate_test();
-    for (i, elt) in m.iter().enumerate() {
-        assert_eq!(i as i32, *elt);
-    }
-    let mut n = LinkedList::new();
-    assert_eq!(n.iter().next(), None);
-    n.push_front(4);
-    let mut it = n.iter();
-    assert_eq!(it.size_hint(), (1, Some(1)));
-    assert_eq!(it.next().unwrap(), &4);
-    assert_eq!(it.size_hint(), (0, Some(0)));
-    assert_eq!(it.next(), None);
-}
-
-#[test]
-fn test_iterator_clone() {
-    let mut n = LinkedList::new();
-    n.push_back(2);
-    n.push_back(3);
-    n.push_back(4);
-    let mut it = n.iter();
-    it.next();
-    let mut jt = it.clone();
-    assert_eq!(it.next(), jt.next());
-    assert_eq!(it.next_back(), jt.next_back());
-    assert_eq!(it.next(), jt.next());
-}
-
-#[test]
-fn test_iterator_double_end() {
-    let mut n = LinkedList::new();
-    assert_eq!(n.iter().next(), None);
-    n.push_front(4);
-    n.push_front(5);
-    n.push_front(6);
-    let mut it = n.iter();
-    assert_eq!(it.size_hint(), (3, Some(3)));
-    assert_eq!(it.next().unwrap(), &6);
-    assert_eq!(it.size_hint(), (2, Some(2)));
-    assert_eq!(it.next_back().unwrap(), &4);
-    assert_eq!(it.size_hint(), (1, Some(1)));
-    assert_eq!(it.next_back().unwrap(), &5);
-    assert_eq!(it.next_back(), None);
-    assert_eq!(it.next(), None);
-}
-
-#[test]
-fn test_rev_iter() {
-    let m = generate_test();
-    for (i, elt) in m.iter().rev().enumerate() {
-        assert_eq!((6 - i) as i32, *elt);
-    }
-    let mut n = LinkedList::new();
-    assert_eq!(n.iter().rev().next(), None);
-    n.push_front(4);
-    let mut it = n.iter().rev();
-    assert_eq!(it.size_hint(), (1, Some(1)));
-    assert_eq!(it.next().unwrap(), &4);
-    assert_eq!(it.size_hint(), (0, Some(0)));
-    assert_eq!(it.next(), None);
-}
-
-#[test]
-fn test_mut_iter() {
-    let mut m = generate_test();
-    let mut len = m.len();
-    for (i, elt) in m.iter_mut().enumerate() {
-        assert_eq!(i as i32, *elt);
-        len -= 1;
-    }
-    assert_eq!(len, 0);
-    let mut n = LinkedList::new();
-    assert!(n.iter_mut().next().is_none());
-    n.push_front(4);
-    n.push_back(5);
-    let mut it = n.iter_mut();
-    assert_eq!(it.size_hint(), (2, Some(2)));
-    assert!(it.next().is_some());
-    assert!(it.next().is_some());
-    assert_eq!(it.size_hint(), (0, Some(0)));
-    assert!(it.next().is_none());
-}
-
-#[test]
-fn test_iterator_mut_double_end() {
-    let mut n = LinkedList::new();
-    assert!(n.iter_mut().next_back().is_none());
-    n.push_front(4);
-    n.push_front(5);
-    n.push_front(6);
-    let mut it = n.iter_mut();
-    assert_eq!(it.size_hint(), (3, Some(3)));
-    assert_eq!(*it.next().unwrap(), 6);
-    assert_eq!(it.size_hint(), (2, Some(2)));
-    assert_eq!(*it.next_back().unwrap(), 4);
-    assert_eq!(it.size_hint(), (1, Some(1)));
-    assert_eq!(*it.next_back().unwrap(), 5);
-    assert!(it.next_back().is_none());
-    assert!(it.next().is_none());
-}
-
-#[test]
-fn test_mut_rev_iter() {
-    let mut m = generate_test();
-    for (i, elt) in m.iter_mut().rev().enumerate() {
-        assert_eq!((6 - i) as i32, *elt);
-    }
-    let mut n = LinkedList::new();
-    assert!(n.iter_mut().rev().next().is_none());
-    n.push_front(4);
-    let mut it = n.iter_mut().rev();
-    assert!(it.next().is_some());
-    assert!(it.next().is_none());
-}
-
-#[test]
-fn test_eq() {
-    let mut n = list_from(&[]);
-    let mut m = list_from(&[]);
-    assert!(n == m);
-    n.push_front(1);
-    assert!(n != m);
-    m.push_back(1);
-    assert!(n == m);
-
-    let n = list_from(&[2, 3, 4]);
-    let m = list_from(&[1, 2, 3]);
-    assert!(n != m);
-}
 
 #[test]
 fn test_hash() {
@@ -256,449 +19,3 @@ fn test_hash() {
 
     assert!(hash(&x) == hash(&y));
 }
-
-#[test]
-fn test_ord() {
-    let n = list_from(&[]);
-    let m = list_from(&[1, 2, 3]);
-    assert!(n < m);
-    assert!(m > n);
-    assert!(n <= n);
-    assert!(n >= n);
-}
-
-#[test]
-fn test_ord_nan() {
-    let nan = 0.0f64 / 0.0;
-    let n = list_from(&[nan]);
-    let m = list_from(&[nan]);
-    assert!(!(n < m));
-    assert!(!(n > m));
-    assert!(!(n <= m));
-    assert!(!(n >= m));
-
-    let n = list_from(&[nan]);
-    let one = list_from(&[1.0f64]);
-    assert!(!(n < one));
-    assert!(!(n > one));
-    assert!(!(n <= one));
-    assert!(!(n >= one));
-
-    let u = list_from(&[1.0f64, 2.0, nan]);
-    let v = list_from(&[1.0f64, 2.0, 3.0]);
-    assert!(!(u < v));
-    assert!(!(u > v));
-    assert!(!(u <= v));
-    assert!(!(u >= v));
-
-    let s = list_from(&[1.0f64, 2.0, 4.0, 2.0]);
-    let t = list_from(&[1.0f64, 2.0, 3.0, 2.0]);
-    assert!(!(s < t));
-    assert!(s > one);
-    assert!(!(s <= one));
-    assert!(s >= one);
-}
-
-#[test]
-fn test_show() {
-    let list: LinkedList<_> = (0..10).collect();
-    assert_eq!(format!("{list:?}"), "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]");
-
-    let list: LinkedList<_> = ["just", "one", "test", "more"].into_iter().collect();
-    assert_eq!(format!("{list:?}"), "[\"just\", \"one\", \"test\", \"more\"]");
-}
-
-#[test]
-fn test_extend_ref() {
-    let mut a = LinkedList::new();
-    a.push_back(1);
-
-    a.extend(&[2, 3, 4]);
-
-    assert_eq!(a.len(), 4);
-    assert_eq!(a, list_from(&[1, 2, 3, 4]));
-
-    let mut b = LinkedList::new();
-    b.push_back(5);
-    b.push_back(6);
-    a.extend(&b);
-
-    assert_eq!(a.len(), 6);
-    assert_eq!(a, list_from(&[1, 2, 3, 4, 5, 6]));
-}
-
-#[test]
-fn test_extend() {
-    let mut a = LinkedList::new();
-    a.push_back(1);
-    a.extend(vec![2, 3, 4]); // uses iterator
-
-    assert_eq!(a.len(), 4);
-    assert!(a.iter().eq(&[1, 2, 3, 4]));
-
-    let b: LinkedList<_> = [5, 6, 7].into_iter().collect();
-    a.extend(b); // specializes to `append`
-
-    assert_eq!(a.len(), 7);
-    assert!(a.iter().eq(&[1, 2, 3, 4, 5, 6, 7]));
-}
-
-#[test]
-fn test_contains() {
-    let mut l = LinkedList::new();
-    l.extend(&[2, 3, 4]);
-
-    assert!(l.contains(&3));
-    assert!(!l.contains(&1));
-
-    l.clear();
-
-    assert!(!l.contains(&3));
-}
-
-#[test]
-fn drain_filter_empty() {
-    let mut list: LinkedList<i32> = LinkedList::new();
-
-    {
-        let mut iter = list.drain_filter(|_| true);
-        assert_eq!(iter.size_hint(), (0, Some(0)));
-        assert_eq!(iter.next(), None);
-        assert_eq!(iter.size_hint(), (0, Some(0)));
-        assert_eq!(iter.next(), None);
-        assert_eq!(iter.size_hint(), (0, Some(0)));
-    }
-
-    assert_eq!(list.len(), 0);
-    assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![]);
-}
-
-#[test]
-fn drain_filter_zst() {
-    let mut list: LinkedList<_> = [(), (), (), (), ()].into_iter().collect();
-    let initial_len = list.len();
-    let mut count = 0;
-
-    {
-        let mut iter = list.drain_filter(|_| true);
-        assert_eq!(iter.size_hint(), (0, Some(initial_len)));
-        while let Some(_) = iter.next() {
-            count += 1;
-            assert_eq!(iter.size_hint(), (0, Some(initial_len - count)));
-        }
-        assert_eq!(iter.size_hint(), (0, Some(0)));
-        assert_eq!(iter.next(), None);
-        assert_eq!(iter.size_hint(), (0, Some(0)));
-    }
-
-    assert_eq!(count, initial_len);
-    assert_eq!(list.len(), 0);
-    assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![]);
-}
-
-#[test]
-fn drain_filter_false() {
-    let mut list: LinkedList<_> = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].into_iter().collect();
-
-    let initial_len = list.len();
-    let mut count = 0;
-
-    {
-        let mut iter = list.drain_filter(|_| false);
-        assert_eq!(iter.size_hint(), (0, Some(initial_len)));
-        for _ in iter.by_ref() {
-            count += 1;
-        }
-        assert_eq!(iter.size_hint(), (0, Some(0)));
-        assert_eq!(iter.next(), None);
-        assert_eq!(iter.size_hint(), (0, Some(0)));
-    }
-
-    assert_eq!(count, 0);
-    assert_eq!(list.len(), initial_len);
-    assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
-}
-
-#[test]
-fn drain_filter_true() {
-    let mut list: LinkedList<_> = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].into_iter().collect();
-
-    let initial_len = list.len();
-    let mut count = 0;
-
-    {
-        let mut iter = list.drain_filter(|_| true);
-        assert_eq!(iter.size_hint(), (0, Some(initial_len)));
-        while let Some(_) = iter.next() {
-            count += 1;
-            assert_eq!(iter.size_hint(), (0, Some(initial_len - count)));
-        }
-        assert_eq!(iter.size_hint(), (0, Some(0)));
-        assert_eq!(iter.next(), None);
-        assert_eq!(iter.size_hint(), (0, Some(0)));
-    }
-
-    assert_eq!(count, initial_len);
-    assert_eq!(list.len(), 0);
-    assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![]);
-}
-
-#[test]
-fn drain_filter_complex() {
-    {
-        //                [+xxx++++++xxxxx++++x+x++]
-        let mut list = [
-            1, 2, 4, 6, 7, 9, 11, 13, 15, 17, 18, 20, 22, 24, 26, 27, 29, 31, 33, 34, 35, 36, 37,
-            39,
-        ]
-        .into_iter()
-        .collect::<LinkedList<_>>();
-
-        let removed = list.drain_filter(|x| *x % 2 == 0).collect::<Vec<_>>();
-        assert_eq!(removed.len(), 10);
-        assert_eq!(removed, vec![2, 4, 6, 18, 20, 22, 24, 26, 34, 36]);
-
-        assert_eq!(list.len(), 14);
-        assert_eq!(
-            list.into_iter().collect::<Vec<_>>(),
-            vec![1, 7, 9, 11, 13, 15, 17, 27, 29, 31, 33, 35, 37, 39]
-        );
-    }
-
-    {
-        // [xxx++++++xxxxx++++x+x++]
-        let mut list =
-            [2, 4, 6, 7, 9, 11, 13, 15, 17, 18, 20, 22, 24, 26, 27, 29, 31, 33, 34, 35, 36, 37, 39]
-                .into_iter()
-                .collect::<LinkedList<_>>();
-
-        let removed = list.drain_filter(|x| *x % 2 == 0).collect::<Vec<_>>();
-        assert_eq!(removed.len(), 10);
-        assert_eq!(removed, vec![2, 4, 6, 18, 20, 22, 24, 26, 34, 36]);
-
-        assert_eq!(list.len(), 13);
-        assert_eq!(
-            list.into_iter().collect::<Vec<_>>(),
-            vec![7, 9, 11, 13, 15, 17, 27, 29, 31, 33, 35, 37, 39]
-        );
-    }
-
-    {
-        // [xxx++++++xxxxx++++x+x]
-        let mut list =
-            [2, 4, 6, 7, 9, 11, 13, 15, 17, 18, 20, 22, 24, 26, 27, 29, 31, 33, 34, 35, 36]
-                .into_iter()
-                .collect::<LinkedList<_>>();
-
-        let removed = list.drain_filter(|x| *x % 2 == 0).collect::<Vec<_>>();
-        assert_eq!(removed.len(), 10);
-        assert_eq!(removed, vec![2, 4, 6, 18, 20, 22, 24, 26, 34, 36]);
-
-        assert_eq!(list.len(), 11);
-        assert_eq!(
-            list.into_iter().collect::<Vec<_>>(),
-            vec![7, 9, 11, 13, 15, 17, 27, 29, 31, 33, 35]
-        );
-    }
-
-    {
-        // [xxxxxxxxxx+++++++++++]
-        let mut list = [2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19]
-            .into_iter()
-            .collect::<LinkedList<_>>();
-
-        let removed = list.drain_filter(|x| *x % 2 == 0).collect::<Vec<_>>();
-        assert_eq!(removed.len(), 10);
-        assert_eq!(removed, vec![2, 4, 6, 8, 10, 12, 14, 16, 18, 20]);
-
-        assert_eq!(list.len(), 10);
-        assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![1, 3, 5, 7, 9, 11, 13, 15, 17, 19]);
-    }
-
-    {
-        // [+++++++++++xxxxxxxxxx]
-        let mut list = [1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20]
-            .into_iter()
-            .collect::<LinkedList<_>>();
-
-        let removed = list.drain_filter(|x| *x % 2 == 0).collect::<Vec<_>>();
-        assert_eq!(removed.len(), 10);
-        assert_eq!(removed, vec![2, 4, 6, 8, 10, 12, 14, 16, 18, 20]);
-
-        assert_eq!(list.len(), 10);
-        assert_eq!(list.into_iter().collect::<Vec<_>>(), vec![1, 3, 5, 7, 9, 11, 13, 15, 17, 19]);
-    }
-}
-
-#[test]
-fn drain_filter_drop_panic_leak() {
-    static mut DROPS: i32 = 0;
-
-    struct D(bool);
-
-    impl Drop for D {
-        fn drop(&mut self) {
-            unsafe {
-                DROPS += 1;
-            }
-
-            if self.0 {
-                panic!("panic in `drop`");
-            }
-        }
-    }
-
-    let mut q = LinkedList::new();
-    q.push_back(D(false));
-    q.push_back(D(false));
-    q.push_back(D(false));
-    q.push_back(D(false));
-    q.push_back(D(false));
-    q.push_front(D(false));
-    q.push_front(D(true));
-    q.push_front(D(false));
-
-    catch_unwind(AssertUnwindSafe(|| drop(q.drain_filter(|_| true)))).ok();
-
-    assert_eq!(unsafe { DROPS }, 8);
-    assert!(q.is_empty());
-}
-
-#[test]
-fn drain_filter_pred_panic_leak() {
-    static mut DROPS: i32 = 0;
-
-    #[derive(Debug)]
-    struct D(u32);
-
-    impl Drop for D {
-        fn drop(&mut self) {
-            unsafe {
-                DROPS += 1;
-            }
-        }
-    }
-
-    let mut q = LinkedList::new();
-    q.push_back(D(3));
-    q.push_back(D(4));
-    q.push_back(D(5));
-    q.push_back(D(6));
-    q.push_back(D(7));
-    q.push_front(D(2));
-    q.push_front(D(1));
-    q.push_front(D(0));
-
-    catch_unwind(AssertUnwindSafe(|| {
-        drop(q.drain_filter(|item| if item.0 >= 2 { panic!() } else { true }))
-    }))
-    .ok();
-
-    assert_eq!(unsafe { DROPS }, 2); // 0 and 1
-    assert_eq!(q.len(), 6);
-}
-
-#[test]
-fn test_drop() {
-    static mut DROPS: i32 = 0;
-    struct Elem;
-    impl Drop for Elem {
-        fn drop(&mut self) {
-            unsafe {
-                DROPS += 1;
-            }
-        }
-    }
-
-    let mut ring = LinkedList::new();
-    ring.push_back(Elem);
-    ring.push_front(Elem);
-    ring.push_back(Elem);
-    ring.push_front(Elem);
-    drop(ring);
-
-    assert_eq!(unsafe { DROPS }, 4);
-}
-
-#[test]
-fn test_drop_with_pop() {
-    static mut DROPS: i32 = 0;
-    struct Elem;
-    impl Drop for Elem {
-        fn drop(&mut self) {
-            unsafe {
-                DROPS += 1;
-            }
-        }
-    }
-
-    let mut ring = LinkedList::new();
-    ring.push_back(Elem);
-    ring.push_front(Elem);
-    ring.push_back(Elem);
-    ring.push_front(Elem);
-
-    drop(ring.pop_back());
-    drop(ring.pop_front());
-    assert_eq!(unsafe { DROPS }, 2);
-
-    drop(ring);
-    assert_eq!(unsafe { DROPS }, 4);
-}
-
-#[test]
-fn test_drop_clear() {
-    static mut DROPS: i32 = 0;
-    struct Elem;
-    impl Drop for Elem {
-        fn drop(&mut self) {
-            unsafe {
-                DROPS += 1;
-            }
-        }
-    }
-
-    let mut ring = LinkedList::new();
-    ring.push_back(Elem);
-    ring.push_front(Elem);
-    ring.push_back(Elem);
-    ring.push_front(Elem);
-    ring.clear();
-    assert_eq!(unsafe { DROPS }, 4);
-
-    drop(ring);
-    assert_eq!(unsafe { DROPS }, 4);
-}
-
-#[test]
-fn test_drop_panic() {
-    static mut DROPS: i32 = 0;
-
-    struct D(bool);
-
-    impl Drop for D {
-        fn drop(&mut self) {
-            unsafe {
-                DROPS += 1;
-            }
-
-            if self.0 {
-                panic!("panic in `drop`");
-            }
-        }
-    }
-
-    let mut q = LinkedList::new();
-    q.push_back(D(false));
-    q.push_back(D(false));
-    q.push_back(D(false));
-    q.push_back(D(false));
-    q.push_back(D(false));
-    q.push_front(D(false));
-    q.push_front(D(false));
-    q.push_front(D(true));
-
-    catch_unwind(move || drop(q)).ok();
-
-    assert_eq!(unsafe { DROPS }, 8);
-}